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* to you under the Apache License, Version 2.0 (the
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package org.apache.cayenne;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.cayenne.cache.MapQueryCache;
import org.apache.cayenne.cache.QueryCache;
import org.apache.cayenne.configuration.web.CayenneFilter;
import org.apache.cayenne.event.EventManager;
import org.apache.cayenne.exp.ValueInjector;
import org.apache.cayenne.graph.CompoundDiff;
import org.apache.cayenne.graph.GraphDiff;
import org.apache.cayenne.graph.GraphEvent;
import org.apache.cayenne.graph.GraphManager;
import org.apache.cayenne.map.EntityResolver;
import org.apache.cayenne.map.LifecycleEvent;
import org.apache.cayenne.map.ObjEntity;
import org.apache.cayenne.query.ObjectIdQuery;
import org.apache.cayenne.query.Query;
import org.apache.cayenne.query.RefreshQuery;
import org.apache.cayenne.reflect.AttributeProperty;
import org.apache.cayenne.reflect.ClassDescriptor;
import org.apache.cayenne.reflect.Property;
import org.apache.cayenne.reflect.PropertyVisitor;
import org.apache.cayenne.reflect.ToManyProperty;
import org.apache.cayenne.reflect.ToOneProperty;
import org.apache.cayenne.util.ObjectContextGraphAction;
/**
* A common base superclass for Cayenne ObjectContext implementors.
*
* @since 3.0
*/
public abstract class BaseContext implements ObjectContext, DataChannel {
/**
* A holder of a ObjectContext bound to the current thread.
*
* @since 3.0
*/
protected static final ThreadLocal<ObjectContext> threadObjectContext = new ThreadLocal<ObjectContext>();
/**
* A holder of a DataChannel bound to the current thread. Used mainly for proper
* contexts and objects deserialization.
*
* @since 3.1
*/
protected static final ThreadLocal<DataChannel> threadDeserializationChannel = new ThreadLocal<DataChannel>();
/**
* Returns the ObjectContext bound to the current thread.
*
* @since 3.0
* @return the ObjectContext associated with caller thread.
* @throws IllegalStateException if there is no ObjectContext bound to the current
* thread.
*/
public static ObjectContext getThreadObjectContext() throws IllegalStateException {
ObjectContext context = threadObjectContext.get();
if (context == null) {
throw new IllegalStateException("Current thread has no bound ObjectContext.");
}
return context;
}
/**
* Binds a ObjectContext to the current thread. ObjectContext can later be retrieved
* by users in the same thread by calling {@link BaseContext#getThreadObjectContext}.
* Using null parameter will unbind currently bound ObjectContext.
*
* @since 3.0
*/
public static void bindThreadObjectContext(ObjectContext context) {
threadObjectContext.set(context);
}
/**
* Binds a DataChannel to the current thread that should be used for deserializing of
* ObjectContexts. An ObjectContext implementation may call
* {@link #getThreadDeserializationChannel()} from its deserialization method to
* attach to the currently active channel.
* <p>
* {@link CayenneFilter} will automatically bind the right channel to each request
* thread. If you are not using CayenneFilter, your application is responsible for
* calling this method at appropriate points of the lifecycle.
*
* @since 3.1
*/
public static void bindThreadDeserializationChannel(DataChannel dataChannel) {
threadDeserializationChannel.set(dataChannel);
}
/**
* Returns the DataChannel bound to the current thread. May return null if none is
* bound (unlike {@link #getThreadObjectContext()} that throws if a context is not
* bound).
*
* @since 3.1
*/
public static DataChannel getThreadDeserializationChannel() {
return threadDeserializationChannel.get();
}
// if we are to pass the context around, channel should be left alone and
// reinjected later if needed
protected transient DataChannel channel;
protected QueryCache queryCache;
/**
* Graph action that handles property changes
*
* @since 3.1
*/
protected ObjectContextGraphAction graphAction;
/**
* Stores user defined properties associated with this DataContext.
*
* @since 3.0
*/
protected Map<String, Object> userProperties;
protected BaseContext() {
graphAction = new ObjectContextGraphAction(this);
}
public abstract void commitChanges();
public abstract void commitChangesToParent();
public abstract Collection<?> deletedObjects();
public DataChannel getChannel() {
return channel;
}
public abstract EntityResolver getEntityResolver();
public abstract GraphManager getGraphManager();
public abstract Persistent localObject(ObjectId id, Object prototype);
public abstract Collection<?> modifiedObjects();
public abstract <T> T newObject(Class<T> persistentClass);
public abstract void registerNewObject(Object object);
public abstract Collection<?> newObjects();
public abstract QueryResponse performGenericQuery(Query query);
@SuppressWarnings("unchecked")
public abstract List performQuery(Query query);
public void prepareForAccess(Persistent object, String property, boolean lazyFaulting) {
if (object.getPersistenceState() == PersistenceState.HOLLOW) {
ObjectId oid = object.getObjectId();
List<?> objects = performQuery(new ObjectIdQuery(
oid,
false,
ObjectIdQuery.CACHE));
if (objects.size() == 0) {
throw new FaultFailureException(
"Error resolving fault, no matching row exists in the database for ObjectId: "
+ oid);
}
else if (objects.size() > 1) {
throw new FaultFailureException(
"Error resolving fault, more than one row exists in the database for ObjectId: "
+ oid);
}
// sanity check...
if (object.getPersistenceState() != PersistenceState.COMMITTED) {
String state = PersistenceState.persistenceStateName(object
.getPersistenceState());
// TODO: andrus 4/13/2006, modified and deleted states are possible due to
// a race condition, should we handle them here?
throw new FaultFailureException(
"Error resolving fault for ObjectId: "
+ oid
+ " and state ("
+ state
+ "). Possible cause - matching row is missing from the database.");
}
}
// resolve relationship fault
if (lazyFaulting && property != null) {
ClassDescriptor classDescriptor = getEntityResolver().getClassDescriptor(
object.getObjectId().getEntityName());
Property propertyDescriptor = classDescriptor.getProperty(property);
// If we don't have a property descriptor, there's not much we can do.
// Let the caller know that the specified property could not be found and list
// all of the properties that could be so the caller knows what can be used.
if (propertyDescriptor == null) {
final StringBuilder errorMessage = new StringBuilder();
errorMessage.append(String.format(
"Property '%s' is not declared for entity '%s'.",
property,
object.getObjectId().getEntityName()));
errorMessage.append(" Declared properties are: ");
// Grab each of the declared properties.
final List<String> properties = new ArrayList<String>();
classDescriptor.visitProperties(new PropertyVisitor() {
public boolean visitAttribute(final AttributeProperty property) {
properties.add(property.getName());
return true;
}
public boolean visitToOne(final ToOneProperty property) {
properties.add(property.getName());
return true;
}
public boolean visitToMany(final ToManyProperty property) {
properties.add(property.getName());
return true;
}
});
// Now add the declared property names to the error message.
boolean first = true;
for (String declaredProperty : properties) {
if (first) {
errorMessage.append(String.format("'%s'", declaredProperty));
first = false;
}
else {
errorMessage.append(String.format(", '%s'", declaredProperty));
}
}
errorMessage.append(".");
throw new CayenneRuntimeException(errorMessage.toString());
}
// this should trigger fault resolving
propertyDescriptor.readProperty(object);
}
}
public void propertyChanged(
Persistent object,
String property,
Object oldValue,
Object newValue) {
graphAction.handlePropertyChange(object, property, oldValue, newValue);
}
public abstract void rollbackChanges();
public abstract void rollbackChangesLocally();
public abstract Collection<?> uncommittedObjects();
/**
* Returns {@link QueryCache}, creating it on the fly if needed.
*/
public QueryCache getQueryCache() {
if (queryCache == null) {
synchronized (this) {
if (queryCache == null) {
// TODO: andrus, 7/27/2006 - figure out the factory stuff like we have
// in DataContext
queryCache = new MapQueryCache();
}
}
}
return queryCache;
}
/**
* Sets a QueryCache to be used for storing cached query results.
*/
public void setQueryCache(QueryCache queryCache) {
this.queryCache = queryCache;
}
/**
* Returns EventManager associated with the ObjectStore.
*
* @since 1.2
*/
public EventManager getEventManager() {
return channel != null ? channel.getEventManager() : null;
}
public GraphDiff onSync(
ObjectContext originatingContext,
GraphDiff changes,
int syncType) {
switch (syncType) {
case DataChannel.ROLLBACK_CASCADE_SYNC:
return onContextRollback(originatingContext);
case DataChannel.FLUSH_NOCASCADE_SYNC:
return onContextFlush(originatingContext, changes, false);
case DataChannel.FLUSH_CASCADE_SYNC:
return onContextFlush(originatingContext, changes, true);
default:
throw new CayenneRuntimeException("Unrecognized SyncMessage type: "
+ syncType);
}
}
GraphDiff onContextRollback(ObjectContext originatingContext) {
rollbackChanges();
return new CompoundDiff();
}
protected abstract GraphDiff onContextFlush(
ObjectContext originatingContext,
GraphDiff changes,
boolean cascade);
/**
* @since 1.2
*/
protected void fireDataChannelCommitted(Object postedBy, GraphDiff changes) {
EventManager manager = getEventManager();
if (manager != null) {
GraphEvent e = new GraphEvent(this, postedBy, changes);
manager.postEvent(e, DataChannel.GRAPH_FLUSHED_SUBJECT);
}
}
/**
* @since 1.2
*/
protected void fireDataChannelRolledback(Object postedBy, GraphDiff changes) {
EventManager manager = getEventManager();
if (manager != null) {
GraphEvent e = new GraphEvent(this, postedBy, changes);
manager.postEvent(e, DataChannel.GRAPH_ROLLEDBACK_SUBJECT);
}
}
/**
* @since 1.2
*/
protected void fireDataChannelChanged(Object postedBy, GraphDiff changes) {
EventManager manager = getEventManager();
if (manager != null) {
GraphEvent e = new GraphEvent(this, postedBy, changes);
manager.postEvent(e, DataChannel.GRAPH_CHANGED_SUBJECT);
}
}
public void invalidateObjects(Collection objects) {
performGenericQuery(new RefreshQuery(objects));
}
/**
* Returns a map of user-defined properties associated with this DataContext.
*
* @since 3.0
*/
protected Map<String, Object> getUserProperties() {
// as not all users will take advantage of properties, creating the
// map on demand to keep DataContext lean...
if (userProperties == null) {
userProperties = new HashMap<String, Object>();
}
return userProperties;
}
/**
* Returns a user-defined property previously set via 'setUserProperty'. Note that it
* is a caller responsibility to synchronize access to properties.
*
* @since 3.0
*/
public Object getUserProperty(String key) {
return getUserProperties().get(key);
}
/**
* Sets a user-defined property. Note that it is a caller responsibility to
* synchronize access to properties.
*
* @since 3.0
*/
public void setUserProperty(String key, Object value) {
getUserProperties().put(key, value);
}
/**
* If ObjEntity qualifier is set, asks it to inject initial value to an object. Also
* performs all Persistent initialization operations
*/
protected void injectInitialValue(Object obj) {
// must follow this exact order of property initialization per CAY-653, i.e. have
// the id and the context in place BEFORE setPersistence is called
Persistent object = (Persistent) obj;
object.setObjectContext(this);
object.setPersistenceState(PersistenceState.NEW);
GraphManager graphManager = getGraphManager();
synchronized (graphManager) {
graphManager.registerNode(object.getObjectId(), object);
graphManager.nodeCreated(object.getObjectId());
}
ObjEntity entity;
try {
entity = getEntityResolver().lookupObjEntity(object.getClass());
}
catch (CayenneRuntimeException ex) {
// ObjEntity cannot be fetched, ignored
entity = null;
}
if (entity != null) {
if (entity.getDeclaredQualifier() instanceof ValueInjector) {
((ValueInjector) entity.getDeclaredQualifier()).injectValue(object);
}
}
// invoke callbacks
getEntityResolver().getCallbackRegistry().performCallbacks(
LifecycleEvent.POST_ADD,
object);
}
/**
* Schedules an object for deletion on the next commit of this context. Object's
* persistence state is changed to PersistenceState.DELETED; objects related to this
* object are processed according to delete rules, i.e. relationships can be unset
* ("nullify" rule), deletion operation is cascaded (cascade rule).
*
* @param object a persistent object that we want to delete.
* @throws DeleteDenyException if a DENY delete rule is applicable for object
* deletion.
* @throws NullPointerException if object is null.
*/
public void deleteObject(Object object) {
new ObjectContextDeleteAction(this).performDelete((Persistent) object);
}
public void deleteObjects(Collection<?> objects) throws DeleteDenyException {
if (objects.isEmpty())
return;
// Don't call deleteObject() directly since it would be less efficient.
ObjectContextDeleteAction ocda = new ObjectContextDeleteAction(this);
// Make a copy to iterate over to avoid ConcurrentModificationException.
for (Persistent object : (ArrayList<Persistent>) new ArrayList(objects))
ocda.performDelete(object);
}
}